Platform: Windows
ISP: Verizon
Type of Internet Connection: DSL
Internet Connection Speed: 5Mbps
Date & Time: May. 4, 2011 18:00 PDT
Frequency: Repeatable
Character Name: Ami Trubble
Race: Lalafell
World: Besaid
Class/Skill Rank: Lancer/46
Physical Level: 50
Area and Coordinates: Broken Water, various
Party or Solo: Party, 7 members
NPC Name: None
Monster Name: None
In-Game Time: Various
Steps:
Base HP, with items, 1853
Ate Grilled Dodo, while in passive mode
HP total increased by 80 HP to 1933
Enter active mode, HP maximum (in Attributes / Gear menu) remains at 1933, but current HP total drops to 1853
Cast cure on self, floating text shows 80 HP gained, but current HP total remains at 1853
Case sacrifice on self, HP gain is the same, but HP regeneration effect will raise current HP to 1933
Entering passive stance, current HP slowly regenerates to 1933

Also tested eating Grilled Dodo while in active mode, with no change.